"The multiverse is no longer a model, it is a consequence of our models.”

~Aurelien Barrau, particle physicist at CERN

The Hollywood blockbuster, The Golden Compass, adapted from the first volume of Pullman's classic sci-fi trilogy, "His Dark Materials" portrays various universes as only one reality among many, but how realistic is this kind of classic sci-fi plot? While it hasn’t been proven yet, many highly respected and credible scientists are now saying there’s reason to believe that parallel dimensions could very well be more than figments of our imaginations.

"The idea of multiple universes is more than a fantastic invention—it
appears naturally within several scientific theories, and deserves to
be taken seriously," stated Aurelien Barrau, a French particle
physicist at the European Organization for Nuclear Research (CERN).

There are a variety of competing theories based on the idea of parallel
universes, but the most basic idea is that if the universe is infinite,
then everything that could possibly occur has happened, is happening,
or will happen.

According to quantum mechanics, nothing at the subatomic scale can
really be said to exist until it is observed. Until then, particles
occupy uncertain "superposition" states, in which they can have
simultaneous "up" and "down" spins, or appear to be in different places
at the same time. The mere act of observing somehow appears to "nail
down" a particular state of reality. Scientists don’t yet have a
perfect explanation for how it occurs, but that hasn’t changed the fact
that the phenomenon does occur.

Unobserved particles are described by "wave functions" representing a
set of multiple "probable" states. When an observer makes a
measurement, the particle then settles down into one of these multiple
options, which is somewhat how the multiple universe theory can be
explained.

The existence of such a parallel universe "does not even assume
speculative modern physics, merely that space is infinite and rather
uniformly filled with matter as indicated by recent astronomical
observations," Max Tegmark, a cosmologist at MIT in Boston,
Massachusetts concluded in a study of parallel universes published by
Cambridge University.

Mathematician Hugh Everett published landmark paper in 1957 while still
a graduate student at Princeton University. In this paper he showed how
quantum theory predicts that a single classical reality will gradually
split into separate, but simultaneously existing realms.

"This is simply a way of trusting strictly the fundamental equations of
quantum mechanics," says Barrau. "The worlds are not spatially
separated, but exist as kinds of 'parallel' universes."

Partly because the idea is so uncomfortably strange, it’s dismissed as
sci-fi by many critics. But there are also many credible, respected
proponents of the theory—a group that is continuously gaining new
adherents as new research unveils new evidence. Some Oxford
research—for the first time—recently found a mathematical answer that
sweeps away one of the key objections to the controversial idea. Their
research shows that Everett was indeed on the right track when he came
up with his multiverse theory. The Oxford team, led by Dr David
Deutsch, showed mathematically that the bush-like branching structure
created by the universe splitting into parallel versions of itself can
explain the probabilistic nature of quantum outcomes.

The work has another strange implication. The idea of parallel
universes would apparently side-step one of the key complaints with
time travel. Every since it was given serious credibility in 1949 by
the great logician Kurt Godel, many eminent physicists have argued
against time travel because it undermines ideas of cause and effect. An
example would be the famous “grandfather paradox” where a time traveler
goes back to kill his grandfather so that he is never born in the first
place.

But if parallel worlds do exist, there is a way around these
troublesome paradoxes. Deutsch argues that time travel shifts happen
between different branches of reality. The mathematical breakthrough
bolsters his claim that quantum theory does not forbid time travel. "It
does sidestep it. You go into another universe," he said. But he admits
that there will be a lot of work to do before we can manipulate
space-time in a way that makes “hops” possible. While it may sound
fanciful, Deutsch says that scientific research is continually making
the theory more believable.

"Many sci-fi authors suggested time travel paradoxes would be solved by
parallel universes but in my work, that conclusion is deduced from
quantum theory itself."

The borderline between physics and metaphysics is not defined by
whether an entity can be observed, but whether it is testable, insists
Tegmark.

He points to phenomena such as black holes, curved space, the slowing
of time at high speeds, even a round Earth, which were all once
rejected as scientific heresy before being proven through
experimentation, even though some remain beyond the grasp of
observation. It is likely, Tegmark concludes that multiverse models
grounded in modern physics will eventually be empirically testable,
predictive and disprovable.

Comments

Multiverse theory is NOT a consequence of any physical models.
It's a consequence of SPECIFIC INTERPRETATIONS of those models.
Quantum mechanics does not require us to follow one interpretation or another to get the right answer.
We have different interpretations because they help us talk about the solutions of the equations in a comfortable familiar way.
What's comfortable for us to think is not how the universe must behave.
If science history teaches us anything, it's that the opposite is most likely true.

There is no reason to believe it will ever be testable, and every reason to believe it will not.

**The onset of big-bang's inflation started gravity, followed by formation of galactic clusters that behave "classically" as Newtonian bodies while continuously reconverting their shares of pre-inflation masses back to energy, and of endless intertwined evolutions WITHIN the clusters in attempts to resist this reconversion.

Astronomically there are two "physics", a "classical physics" behaviour of and between galactic clusters, and a "quantum physics" behaviour within galactic clusters.**

A. "Heavyweight galaxies in the young universe", at

http://www.sciencenews.org/view/generic/id/42419/title/Heavyweight_galaxies_in_the_young_universe
New observations of full-grown galaxies in the young universe may force astrophysicists to revise their leading theory of galaxy formation, at least as it applies to regions where galaxies congregate into clusters.

1. According to the standard model, which describes all the forces in nature except gravity, all elementary particles were born massless. Interactions with the proposed Higgs field would slow down some of the particles and endow them with mass. Finding the Higgs — or proving it does not exist — has therefore become one of the most important quests in particle physics.

However, for a commonsensible primitive mind with a commonsensible universe represented by
E=Total[m(1 + D)], this conceptual equation describes gravity. It does not explain gravity. It describes it. It applies to the whole universe and to every and all specific cases, regardless of size.

2. Thus gravity is simply another face of the total cosmic energy. Thus gravity is THE cosmic parent of phenomena such as black holes and life. It is the display of THE all-pervasive-embracive strained space texture, laid down by the expanding galactic clusters, also noticed within the galactic clusters in the energy backlashes into various constructs of temporary constrained energy packages.

3. "Extrapolation of the expansion of the universe backwards in time to the early hot dense "Big Bang" phase, using general relativity, yields an infinite density and temperature at a finite time in the past. At age 10^-35 seconds the Universe begins with a cataclysm that generates space and time, as well as all the matter and energy the Universe will ever hold."

At D=0, E was = m and both E and m were, together, all the energy and matter the Universe will ever hold. Since the onset of the cataclysm, E remains constant and m diminishes as D increases.
The increase of D is the inflation, followed by expansion, of what became the galactic clusters.

At 10^-35 seconds, D in E=Total[m(1 + D)] was already a fraction of a second above zero. This is when gravity started. This is what started gravity. At this instance starts the space texture, starts the straining of the space texture, and starts the "space texture memory", gravity, that may eventually overcome expansion and initiate re-impansion back to singularity.

D. Commonsensible conception of the forces other than gravity

The forces other than gravity are, commonsensibly, forces involved in conjunction with evolution within the galactic clusters:

http://royalsociety.org/downloaddoc.asp?id=4770

The farthest we go in reductionism in Everything, including in Life, we shall still end up with wholism, until we arrive at energy. Energy is the base element of everything and of all in the universe. At the beginning was the energy singularity, at the end will be near zero mass and an infinite dispersion of the beginning energy, and in-between, the universe undergoes continuous evolution consisting of myriad energy-to-energy and energy-to-mass-to-energy transformations.

The universe, and everything in it, are continuously evolving, and all the evolutions are intertwined.

E. PS to "On Cosmic Energy And Mass Evolutions"

As mass is just another face of energy it is commonsensible to regard not only life, but mass in general, as a format of temporarily constrained energy.

It therefore ensues that whereas the expanding cosmic constructs, the galaxies clusters, are - overall - continuously converting "their" original pre-inflation mass back to energy, the overall evolution WITHIN them, within the clusters, is in the opposite direction, temporarily constrained
energy packages such as black holes and biospheres and other energy-storing mass-formats are precariuosly forming and "doing best" to survive as long as "possible"...

When the universe was very young, and still superhot from the aftermath of the Big Bang, plasma should have been the only state of matter around. And that’s what scientists at Brookhaven expected to see when they smashed gold ions together at 99.99 percent of the speed of light using a machine called RHIC (for Relativistic Heavy Ion Collider). RHIC physicists thought the ion collisions would melt the gold’s protons and neutrons into a hot plasma of quarks and gluons at a temperature of a trillion kelvins, replicating conditions similar to those a microsecond after the birth of the universe. But instead of a gaslike plasma, the physicists reported in 2005, RHIC served up a hot quark soup, behaving more like a liquid than a plasma or gas."

G. The expectation of Brookhaven scientists was a bit unrealistic

The "aftermath of the Big Bang" lasted much less than 10^-35 seconds. This is evidenced by the fact that "Gravity Is THE Manifestation Of The Onset Of Cosmic Inflation Cataclysm":

http://www.the-scientist.com/community/posts/list/184.page#1950
and
http://www.the-scientist.com/community/posts/list/184.page#1982

With all respect due to the scientists at Brookhaven it is unrealistic to expect that they can recreate the state of pre big-bang energy-mass singularity. Commonsense is still the best scientific approach.

A new truth always has to contend with many difficulties,” the German physicist Max Planck said decades ago. “If it were not so, it would have been discovered much sooner.”

b. IMO gravity is attempted reversal of inflation

To me, a simple uninformed one, E=mc^2 is a derived formula, whereas E=Total[m(1 + D)] is a commonsensical descriptive concept.

I intuitively regard both the ultracold and superhot liquids as being in a confined space and "striving but unable" to overcome D, to render D=0.

I also intuitively regard our accelerated collisions smashups as attempted "reverse inflations" in the sense that Newton's law of universal gravitation seems to me as "reverse inflation".

I. An epilogue and a prologue

Here ends the basic story of Energy, Mass, Gravity and Galaxies Clusters. For us, humans, this is the prologue to the story of Life's Evolution, briefly presented in "Updated Life's Manifest May 2009".

So wait, if someone goes back in time (and thus to a different universe) and dies, does that mean they die in our world or the other? I mean, when they go back in time, they create many different worlds with the results of their trip. Does this mean that, even if they die, they would come back, no matter what? I mean, even if one of this person (I'll call him Steve) from one universe went back in time, he creates an infinite amount of different universes, which are all tied to this one event. Since they all happen simultaneously, doesn't that mean that Steve will come back, perhaps even a billion times over?

may there are paralle unvires and when we sleep we tapping into those places looking at are self in ohter demion and that could why we dream and cant explain strange people is because we are looking into another world. theroy could be by the way hi Dr.michio kaku you are great love your movies

What no one has thought about is that you may very well be in an alternate universe. It's just the alternate you. You could be president, you could be a slave, you could be an inventor.
Another thing I want to mention: the universe is finite. However, it increases without bound. Meaning it has an end. That end just keeps growing, so that we can never say where the end exactly is at any given point in time.

i watched a programme on tv today about this and although it's still in the lines of a theory, there's quite a lot of evidence that it's true. i mean, look at all the proven scientific theories it's based on!
i would like to be in a universe that humans are sensitive to their enviroment and the rest of the human race, in a universe with no wars, no global warming, and any other of the horrible things that happened in history.
i wish......

Hi
I have discovered what I think is a parallel reality to our own. I've created a blog about it and I continue to delve into it to try to understand it better. There are creatures there that contact me physically, if anyone wants to read about it they can check-out my URL and contact me with any questions, or if you know a way I could prove this to science in an experimental setting, say, videoed and with sensors placed on my skin to detect the contact.
I haven't got the time to read any other comments right now but I'll come back later...

Perhaps when we die, Heaven or Hell is the TYPE of parallel universe we end up in. What kind of energy or "soul" we have HERE will determine where our energy, be it positive or negative, takes us. Yes, I am a science loving Christian who believes science and God can coincide. Just MY two cents on the whole parallel universe idea!

the universe isn't exactly infinite, but it is impossible to reach it's end, because the expanding of this universe is the speed of light+. But if the universe is so big, there have to be level 1 universes. I am not certain of level 3's though. I am SO glad I am not in the universe where Michelle Bachmann is a dictator. Maybe in one I'm Hitler's son.... I have had bad visions just now.

First, the assumption that each parallel universe has different time-line is wrong. The time-line in each case is a branch of a singularity. Yes, I'm referring to the branches that occurs when a person chose to make a right turn, the other universe a left turn was made. Same time-line different branches.

Next here is a question too ponder. If time & space are infinite, why do we remember the past, but not the future? If you say the future hasn't happened yet, you're mistaken. Infinite means no boundaries, every line has a beginning & an end. Just think about it. I would very much like too hear the different conclusions everyone comes up with.